6o 



BOTANICAL GAZETTE 



[JANUARY 



embryo sac ceases to develop after a few nuclei have been formed in it, 

 and is pushed aside by the hypertrophic inner integument. This 

 envelope, normally composed of a few flattened cells overlying the 

 sac, in this variety of the species early takes on a very active growth, 

 forming a mass of cells which, as it comes to maturity, splits up into 

 rounded bodies simulating the embryo of the genus/ 1 The forma- 

 tion of embryos is often incomplete and growth then results in amor- 

 phous masses; but on the other hand, it is often successful, and 



gives such seed-contents, consisting of several 



well-made embryos, as that 

 (fig 



figured 



herewith 



form 



for the normal embryo has neither suspensor nor 

 cotyledons. But that cells of the inner integu- 

 ment, ordinarily forming a saccate one-celled 

 layer, with not the remotest resemblance to an 

 embryo, should so much change their habits, and 

 in the transformation should select the fashion, 

 though simple, of embryos, is sufficiently singular. 

 I look upon the process as homoeotic in its 



Fig. I8 .-Seed of natUre - 

 Spiranthes cernua The 



(lowland form). 



formation of embryo 



season, 

 may digress 



pendent of pollination, as I have proved by 



carefully castrated and guarded flowers— an 



ant item for a species blooming so late in the 



The biological significance of the process, indeed, is — if I 



that the plant by this means combines 



methods 



duction with the swiftness of dispersal and range of dissemination 

 secured by the seed apparatus. This is doubtless the combination 



circumstances 



apogamy in Compositae also. 



In Sp 



cernua, homoeosis 



supervening in the integument has doubtless contributed to the 

 abundance of the species in suitable soils from Massachusetts and 



search for the polyembry 



much 



(d) Still more remarkable is the transference, discovered by 



Rhodora 



** 



